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Question #46281
The Question
A localized population of an entomophilous Solanaceae species experiences a severe decline in its specific insect pollinator due to pesticide drift. The adult plants remain physiologically viable, exhibiting normal vegetative growth and an intact floral formula (actinomorphic, bisexual, K(5) C(5) A5 G(2)). However, the plant population rapidly approaches localized extinction. Which of the following statements regarding the population dynamics and ecological consequences of this scenario is INCORRECT?
Options
- A.
The population's intrinsic rate of natural increase (r) becomes negative primarily due to a drastic reduction in the per capita birth rate, despite a stable adult death rate.
- B.
This scenario exemplifies the 'Rivet Popper hypothesis', where the loss of a critical mutualist disproportionately disrupts ecosystem services, leading to co-extinction.
- C.
The population's age pyramid will rapidly shift towards an urn-shaped structure, indicating a declining population where pre-reproductive individuals outnumber reproductive individuals.
- D.
The failure of sexual reproduction results in a demographic decline where the net reproductive rate falls below replacement levels, despite the physiological integrity of the adult sporophytes.
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Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Evolutionary_Exception
Tackle problems where standard rules evolve or change based on specific environmental constraints.
Concepts Behind This Question
Solanaceae Floral Formula|Population Density Estimation|Rivet Popper Hypothesis
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize that an 'urn-shaped' pyramid means a declining population but fail to remember the exact quantitative relationship between the age cohorts (Pre-reproductive < Reproductive).
The question uses a complex ecological scenario (pollinator loss, Rivet Popper, floral formula) to distract the student from the fundamental demographic definition trap hidden in Option C.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Morphology of Flowering Plants - Class 11 |
| Concept | Solanaceae Floral Formula |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |